Bearers of next generation communication networks have been moving to IP (Internet Protocol, internet protocol) bearers. From the perspective of the development of communication networks, a progress, from traditional circuit switch networks to IP packet switching networks with control-bearer separation, and then to all IP multimedia networks, has been experienced. End-to-end QoS (Quality of Service, quality of service) issues have to be considered during the evolution to all IP networks to provide customer with satisfied services (particularly, real-time services). Because IP networks may provide more kinds of services (such as, multimedia call, file download, webpage browse, etc), it is necessary to enable networks to detect different service streams, perform statistics on charging information, such as traffic amount, duration etc, and report to charging centers. In order to solve the QoS and stream-based charging issues, a PCC (Policy and Charging Control, policy and charging control) framework has been defined by 3GPP (Third Generation Partnership Project, third generation partnership project). The networks are able to detect different service streams and QoS control, charging statistic and other requirements can be realized for those service streams through the framework.
In the PCC framework, a UE (User Equipment, user equipment) can establish an IP-CAN (IP-Connectivity Access network, IP-connectivity access network) session after assigned with an IP address which is addressable in the PDN (Public Data Network, public data network). In order to satisfy different QoS requirements, IP-CAN bearers (Bearer) with different QoS requirements can be established in a same IP-CAN session. For IP-CAN bearers, they can be categorized into GBR (Guaranteed Bandwidth, GBR) bearers and non-GBR bearers, wherein the default is non-GBR. In general, GBR bearers are used for bandwidth-sensitive real-time services, such as, VoIP (Voice over Internet Protocol, voice over internet protocol) media stream, video stream, etc; while non-GBR bearers are used for bandwidth-insensitive non-real time services and some real-time services having less bandwidth requirements, such as FTP (File Transfer Protocol, file transfer protocol) download, HTTP (Hyper Text Transfer Protocol, hypertext transfer protocol) browse, email (electronic mail, electronic mail), VoIP signaling stream etc.
Presently, operators can realize excellent control over QoS and charging etc for bearer-layer data streams through the PCC framework, to shield upward particular transport network details from the service layer and sense downward transport network resource usage. On one side, PCRF (Policy and Charging Rule Function, policy and charging rule function) may develop corresponding strategies according to session negotiation information indicated by the service layer to control bearer-layer network resource use; on the other side, when the use of underlying bearers has changed, for example, radio bearer loss due to a user entering a uncovered area, a gateway fault, etc, the service layer can be notified through a reporting mechanism, enabling the service layer to change accordingly, provide corresponding strategies.
However, in the prior art, when an eNB (eNodeB, Evolved Node B) needs to release the signaling connection with a UE and its all radio bearers, a PGW (PDN Gateway, Packet Data Network Gateway, packet data network gateway) is notified through a bearer release mechanism, thereby the PCRF and AF (Application Function, application function) are notified. For GBR (Guaranteed bandwidth, guaranteed bandwidth) bearers, since they are substantially adopted for real-time service transport, abnormally released radio bearers, even for a short time, may cause service interrupts, the release of GBR bearers is reasonable. However, for non-GBR bearers, adopting a mechanism releasing non-GBR bearers may affect other services bound to those non-GBR bearers, and lead to an IP address release defect caused by the release of default bearers.